JPH0823580B2 - In-vehicle navigator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vehicle-mounted navigator.

2. Related Art FIG. 5 shows the structure of a conventional vehicle-mounted navigator.
Is a GPS (Globa
l Positioning System) A receiver, 10 is a mileage detecting means for detecting a mileage of a vehicle between respective current positions by detecting a rotational speed of wheels and the like, and 2 is a map data of a road or the like. The auxiliary storage means 3 is a calculation control means for correcting the current position obtained by the GPS receiver 1 as described later and superimposing the map data stored in the auxiliary storage means 2 on the display means 4. , This arithmetic control means 3
Is composed of a central processing unit (CPU), a ROM (read only memory) in which an execution program of the CPU is stored, and a microcomputer having a RAM (random access memory) having a work area of the CPU and the like.

 Next, the operation of the above conventional example will be described.

In FIG. 5, the arithmetic control unit 3 first determines a plurality of travel route candidates that the vehicle may travel based on the current position received by the GPS receiver 1 and the map data stored in the auxiliary storage unit 2. Select (Candidate route selection means 3
1).

Then, the arithmetic control unit 3 calculates the correlation coefficient between the current position and the plurality of travel candidate routes based on the current position received by the GPS receiver 1 and the travel distance detected by the travel distance detection unit 10, Determines one traveling route that the vehicle actually travels (correlation coefficient calculating means 32).

Next, the average of the determined correlation coefficients of the travel route is calculated by GPS.
The offset is determined as the offset of the current position received by the receiver 1 (GPS offset determining means 33), this offset is removed from the current position (offset removing means 34), and the current position from which this offset has been removed and the map data The map is superimposed and displayed on the display means 4.

Problems to be Solved by the Invention However, in the above-mentioned conventional vehicle-mounted navigator, the GP
When the satellites received by the S receiver 1 are switched, the current position obtained by the GPS receiver 1 (x points in the figure) is the actual current position (roads r ₂ , r ₃ ) as shown in Fig. 2 (c). ) And an offset, which is an error component that fluctuates in a long cycle, and an error component that is smaller than this offset, until the next offset is calculated, the current road and the like on the displayed map There is a problem that the positions do not match and the current position cannot be displayed accurately.

In particular, when the road in the map data of the auxiliary storage means 2 is complicated, there is a problem that it cannot be accurately displayed on which road the vehicle is traveling.

In view of the above problems, it is an object of the present invention to provide a vehicle-mounted navigator that can accurately display the current position in a short time even when the satellite received by the GPS receiver is switched.

Means for Solving the Problems In order to solve the above problems, the present invention stores map data and a GPS receiver that receives data from satellites, calculates a current position, and sequentially outputs the calculation result. Map data storage means, a candidate path selection means for selecting a plurality of candidate paths from the map data of the map data storage means based on the output result of the GPS receiver, and a travel distance detection for detecting a travel distance from vehicle travel data. Means and a travel distance of the travel distance detection means, a representative point on a plurality of candidate paths is calculated, an average and a variance of correlation coefficients between the representative point and the current position are calculated, and one candidate path is obtained from the variance. Means for determining the path, offset removing means for removing the average of the correlation functions of the candidate paths determined by the path determining means from the current position based on the output result of the GPS receiver, and this offset Display means for superimposing and displaying the current position from which the offset has been removed by the map removing means and the map data of the map data storage means, and when the satellite that received the data has switched, the path determination means The correlation coefficient is reset, and the correlation coefficient is calculated using the current position after the offset removal immediately before the switching.

Effect The present invention has the above-described configuration for displaying the current position from which the offset has been removed and the map of the map data in an overlapping manner.
The current position can be displayed accurately, and when the satellite switches,
Since the current position and the correlation coefficient between the plurality of travel candidate routes are calculated to determine one travel route, the sampling data for the calculation is small, and therefore the current position can be accurately displayed in a short time. can do.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an in-vehicle navigator according to the present invention, and FIG. 2 (a) is an explanatory diagram of current position data and map data from the GPS receiver of FIG. FIG. 2B is an explanatory diagram of the current position data from the GPS receiver and the traveling distance data from the traveling distance detecting means in FIG.
FIG. 3C is an explanatory diagram of the offset and variation of the current position data from the GPS receiver of FIG. 1, FIG. 3A,
(B) and (c) are flowcharts for explaining the operation of the vehicle-mounted navigator of FIG. 1, FIG. 4 (a),
(B), (C), and (D) are operation explanatory views of the vehicle-mounted navigator of FIG. 1, and the same reference numerals are given to the same components as those shown in FIG.

In FIG. 1, reference numeral 9 indicates the satellite reception number and the second number.
The GPS (Global positioning System) receiver for sequentially obtaining the data of the current positions P _{0 to} P ₁₃ of the vehicle as shown in FIG. travel distance detecting means for detecting a travel distance l ₁ to l ₁₃ of the current position _{P 0 -P 1, P 1 -P} 2 ~ between the vehicle as shown in (b), 2, FIG. 2 (b) , Road r ₁ ~ as shown in (c)
The auxiliary storage means stores the map data having r ₄ .

As shown in FIG. 2C, the road r _j (j
= 1 to 4) and the current position P _{0 to} P obtained from the GPS receiver 9
There are offsets and variations among the ₁₃ data for each satellite.

Reference numeral 30 denotes arithmetic control means for correcting the current position obtained by the GPS receiver as described later and superimposing the map data stored in the auxiliary storage means 2 on the display means 4 for display. 30 is a central processing unit (CPU) and C
It is configured by a microcomputer having a ROM (Read Only Memory) in which a PU execution program is stored and a RAM (Random Access Memory) having a CPU work area and the like.

If the arithmetic and control unit 30 is regarded as a function of a microcomputer, the current positions P _{0 to} P ₁₃ sequentially received by the GPS receiver 9 and the map data (roads r _{1 to} r ₄₎ stored in the auxiliary storage unit 2 will be described. ), A candidate route selection means 31 for selecting a plurality of traveling candidate routes in which the vehicle may travel,
Based on the current positions P _{0 to} P ₁₃ received by the GPS receiver 9 and the travel distances l _{1 to} l ₁₃ detected by the travel distance detecting means 10, the phases of the current positions P _{0 to} P ₁₃ and the plurality of travel candidate routes are calculated. The correlation coefficient calculating means 32 for calculating the number of relationships (average, variance) to determine one travel route along which the vehicle actually travels, and the average of the correlation coefficients of the determined travel candidate routes for the GPS receiver 9
Current position storage means and the GPS offset determination means for determining an offset of the current received position P ₀ to P _13, the current position obtained by removing the offset from the current position P ₀ to P ₁₃ by 36
And an offset removing means 34 for storing the current position and the map of the map data stored in the auxiliary storage means 2 on the display means 4.

The arithmetic control means 30 also detects the satellite switching detection means 34 for detecting the satellite switching by the satellite reception number received by the GPS receiver 9 and the previous time of the current position storage means 36 when the satellite switching is performed. Current position and mileage detection means 10
Based on the current mileage detected by GPS receiver 9
The present position estimating means 35 for calculating the correlation coefficient between the present position from this time and the plurality of travel candidate routes, determining one travel route and estimating the current position of the vehicle.

Next, the operation of the above-described embodiment, particularly the operation of the arithmetic control means 30, will be described with reference to FIGS.

In step 41 shown in FIG. 3A, the arithmetic and control unit 30 receives the satellite reception number and the current position P ₀ from the GPS receiver 9.
Data is input to this data RAM, and the process proceeds to step 42 and the candidate route selection routine shown in FIG.

At step 421 shown in FIG. 3B, the current position P
Considering the offset and variation of ₀ , as shown in FIG. 4 (a), the current position P ₀ is calculated from the map data of the auxiliary storage means 2.
A circular area S on the map centered around is calculated, and then in step 422, the area S in which the vehicle may travel
Select road r _j in.

Incidentally, in FIG. 4 (a), the roads r ₁ and r ₂ are located in the area S, so these are selected.

In the following step 423, for example, the current position P ₀ is the road r ₁ , r
_The representative points F and E and the road r _{1 which} are respectively orthogonal to ₂ are areas S
Point C intersecting the border, D, point road r ₂ intersect the boundary of the region S A, by selecting the B, the current position P ₀
The points A to F on the roads r ₁ and r ₂ corresponding to are selected.

In step 424, the road r ₁
Two-way candidate routes R ₁₆ and R ₁₅ at the point C above and the representative point F
Bidirectional candidate routes R ₁₄ and R ₁₃ and bidirectional candidate routes R ₁₂ and R ₁₁ at point D, and bidirectional candidate routes at point A on road r _2.
Bidirectional candidate routes R ₂₃ , R between R ₂₁ , R ₂₂ and representative point E
By selecting ₂₄ and the bidirectional candidate routes R ₂₅ and R ₂₆ of the point B, the bidirectional candidate routes Rjk (j = 1, 2) starting from the points A to F of the roads r ₁ and r ₂ are selected. , K = 1 to 6) are selected, and the process proceeds to step 43 shown in FIG.

In this process, if the offset of the current position data is determined by the previous process, that value is taken into consideration.

At step 43, the current position Pi (i
= 1)) and the traveling distance l _i from the traveling distance detecting means 10 is RA
The data is taken into M, and the routine proceeds to step 44 and the correlation coefficient calculation routine shown in FIG.

In step 441 shown in FIG. 3C, the candidate route R
The counter j indicating the road number of jk is incremented, and it is determined in step 441a whether or not the satellite has been switched by the number received by the GPS receiver 9.

If the satellite has switched, step 450 described below
If the satellite does not switch, the process proceeds to step 442, and the counter k indicating the direction of the candidate route Rjk and the points A to F is incremented.

In the following step 443, By calculating the point Pijk corresponding to each current position Pi for each candidate route Rjk, and then step 44
In 4, the distance between each point Pijk and the current position Pi Is calculated, and in the following step 445, the average and variance for each candidate route are calculated.

In step 446, it is determined whether the average and the variance exceed the threshold value. If the average and variance exceed the threshold value, the process proceeds to step 447 to exclude the candidate route and the process proceeds to step 448. If the average route and the variance do not exceed the threshold value, the process directly proceeds to step 448.

Here, FIG. 4B shows the distance between each representative point Pi ₂₃ and the current position Pi on the candidate route R ₂₃ in the direction opposite to the actual traveling direction. In this case, since the y component of the variance σ gradually increases, this candidate route R ₂₃ is excluded.

Further, FIG. 4C shows the distance between each representative point Pi ₂₄ and the current position Pi on the candidate route R _{24 on} which the vehicle actually travels. In this case, the candidate route R ₂₄ is not excluded because both the mean and the variance are small.

In FIG. 3 (C), in steps 448 and 449, it is determined whether or not the calculation has been completed for all the candidate routes Rjk, and if not completed, the process returns to steps 442 and 441 to execute the above processing. When finished, Fig. 3 (B)
Proceed to step 45 shown in.

While executing this correlation coefficient calculation routine, etc.
When it is determined that the satellite is switched by the number received by the S receiver 9, the process branches from step 441a to steps 450 and 451.

In step 451 the mean and variance are reset, and in the following step 452, the representative point is moved to the position P (i-
1) j and the traveling distance li obtained by the traveling distance detecting means 10.
Is added.

In step 453, the distance between the previous and current position Then, in step 454, the average and variance are calculated, and the flow advances to step 449.

In FIG. 3A, in step 45, it is determined whether or not there is one candidate route Rjk that has not been excluded, and whether the variance is smaller than that of other candidate routes Rjk. It is determined whether or not the route has been determined. If not determined, the process returns to step 43 and thereafter to execute the above-described correlation coefficient calculation routine and the like.

If it is determined in step 45 that one route has been determined, the process proceeds to step 46 to determine the offset (= average) of that route (road r ₁ shown in FIG. 4C), and then in step 47, GPS Remove the offset from the current position Pi from the receiver 1.

In step 48, the current position is stored, and in step 49,
For example, it is determined whether or not the satellite switching is completed by determining whether or not a predetermined time has passed since the satellite switching (step 441a). If the satellite switching is not completed, the process returns to step 41 and the satellite switching is performed. When the process is completed, the process proceeds to step 50 to reset the satellite switching mode and returns to step 41, and the current position on the map is displayed on the display means 4 with a cursor or the like.

Incidentally, FIG. 4D shows the case where the offset is previously determined, and the area S becomes smaller, so that the route can be easily determined.

Therefore, according to the above embodiment, the travel route is determined from the current position Pi from the GPS receiver 9, and the current position Pi is determined.
The current position can be accurately displayed to remove the offset of.

In addition, when the satellite is switched, the average and variance for previous offset calculation are reset, and in order to calculate a new offset from the vehicle estimated position immediately before the satellite switched, data with a small sampling number is used. The offset can be calculated with high accuracy, and thus the correct current position can be displayed in a short time.

As described above, according to the present invention, when the satellite is switched, the present invention calculates the correlation coefficient between the current position and the plurality of travel candidate routes based on the previous current position and the traveled distance to calculate one Since the travel route is determined, the sampling data for calculation is reduced, and therefore the current position can be accurately displayed in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an in-vehicle navigator according to the present invention, and FIG. 2 (a) is an explanatory diagram of current position data and map data from the GPS receiver of FIG. FIG. 2B is an explanatory diagram of the current position data from the GPS receiver and the traveling distance data from the traveling distance detecting means in FIG.
FIG. 3C is an explanatory diagram of the offset and variation of the current position data from the GPS receiver of FIG. 1, FIG. 3A,
(B) and (c) are flowcharts for explaining the operation of the vehicle-mounted navigator of FIG. 1, FIG. 4 (a),
(B), (c), and (d) are operation | movement explanatory drawing of the vehicle-mounted navigator of FIG. 1, and FIG. 5 is a block diagram which shows the conventional vehicle-mounted navigator. 2 ... auxiliary storage means, 4 ... display means, 9 ... GPS receiver, 10 ... mileage detection means, 30 ... arithmetic control means, 31
...... Candidate route selection means, 32 …… Correlation coefficient calculation means, 33 ・ ・ ・
… GPS offset determining means, 34… offset removing means.

Claims (1)

[Claims] 1. A GPS receiver that receives data from a satellite, calculates a current position, and sequentially outputs the calculation result, a map data storage unit that stores map data, and an output result of the GPS receiver. Candidate path selecting means for selecting a plurality of candidate paths from the map data of the map data storage means,
A mileage detection unit that detects the mileage from the mileage data of the vehicle, and a representative point on a plurality of candidate routes is calculated from the mileage of the mileage detection unit, and the average of the correlation coefficient between the representative point and the current position. , A variance is calculated, and a route determining means for determining one candidate route from the variance, and an average of the correlation functions of the candidate routes determined by the route determining means are removed from the current position based on the output result of the GPS receiver. An offset removing means, and a display means for superimposing and displaying the current position from which the offset has been removed by the offset removing means and the map data of the map data storage means, when the satellite that received the data has switched, An in-vehicle system characterized in that the correlation coefficient of the path determining means is reset, and the correlation coefficient is calculated using the current position after the offset removal immediately before the switching. Navigator.